Rust

CoSign PKCS7/CMS Signed Data

See more Digital Signatures Examples

Demonstrates how to add a 2nd signature to a CMS SignedData. This is to add an additional signature, SignerInfo and certificate(s) to an existing CMS signed data.

In this example, we cosign an existing pdf.p7s

Note: The CoSign method is added in Chilkat v9.5.0.89.

Rust

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

let crypt = chilkat::Crypt2::new();
let cert = chilkat::Cert::new();

// If loading from a smart card, set the smartcard PIN.
cert.set_smart_card_pin("0000");

// Load a certificate in some way, such as from a smart card.
// Chilkat provides other methods to load from a .pfx, .pem, or from the Windows certificate stores..
if cert.load_from_smartcard("").is_err() {
    println!("{}", cert.last_error_text());
    return;
}

if crypt.set_signing_cert(&cert).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

// Load the file to be co-signed.
// NOTE:  This is to cosign a PDF file contained within a CMS (PKCS7) message.
// (In other words, the PDF is contained within the CMS SignedData, rather than the other way around
// where a CMS signature is contained within a PDF.  Use Chilkat's PDF class to sign a PDF, which is
// to embed a CMS signature within the PDF.)
let bd = chilkat::BinData::new();
if bd.load_file("qa_data/p7s/cosign/sample.pdf.p7s").is_err() {
    println!("Failed to load pdf.p7s input file.");
    return;
}

// bd2 will contain the co-signed result.
let bd2 = chilkat::BinData::new();
if crypt.co_sign(&bd, &cert, &bd2).is_err() {
    println!("{}", crypt.last_error_text());
    return;
}

if bd.write_file("qa_output/cosigned.pdf.p7s").is_err() {
    println!("Failed to save pdf.p7s output file.");
    return;
}

println!("Success!");